PIA xv: 
All the figures on this Plate are from specimens in my Collection from Lummaton, except where 
otherwise stated. 
SPROPHEODONTA IRREGULARIS, F. Rémer, sp. (Page 151.) 
Fia. 
1. Ventral valve of a large specimen, which shows the irregular sinus and the frequent divarication 
of the ribs. Wolborough. 
ORTHOTETES DISTORTUS, Barrande, sp. (Page 147.) 
2. Ventral valve of a highly distorted specimen, enlarged. 
STROPHEODONTA INTERSTRIALIS, Phillips, sp. (Page 151.) ; 
3. Upper view of an extreme variety with strong corrugations, and about twelve major ribs, 
enlarged. (The valve is geniculated, and the minor ribs are present though too fine to be 
depicted.) 
4. Another similar specimen with only six or seven major ribs, enlarged. (The minor ribs are 
clearly seen under a lens.) 
N.B.—A series of many graduated specimens exist, connecting this variety with the typical 
form of the shell. (The ruge are sometimes seen on much larger specimens than those figured.) 
Onruis? sp. (Page 144.) 
. Valve, showing the peculiar arrangement of the ribs in low convex groups, enlarged. 
nn 
OrTHIS PULCHERRIMA, n. sp. (Page 145.) 
6. Dorsal view of a rather injured specimen. 6a, lateral view, showing the greater distance of the 
beak of the ventral valve. 60, rear view (ventral valve uppermost). All enlarged. 
SKENEDIUM AREOLA, Quenstedt, sp. (Page 143.) 
7. Rear view of a ventral valve with a low beak. 
8. Ventral view of the large variety with numerous small ribs. 
STRICKLANDINIA? sp. (Page 125.) 
9. Dorsal valve, showing the straight hinge-line, the coarse divaricating ribs, and the steep sub- 
angular fold, enlarged. 
id 
PRODUCTELLA FRAGARINA, n. sp. (Page 155.) 
10. Ventral view of a large but imperfect specimen, enlarged. (The outline is roughly restored from 
a smaller but more perfect specimen.) 
11. Dorsal view of another specimen, showing the pitted surface of the concave dorsal valve, enlarged. 
1la, ventral view, showing the regular arching lines of tubercles. 11 0, lateral view. 
PropuUcrELLA, n. sp. (Page 156.) 
12. Ventral valve of a specimen showing the numerous elongate tubercles and the regular lines of 
growth, enlarged. 12a, portions of surface magnified, showing the finer radiations. 
Cuonetis Harprensis, Phillips, sp.? (Page 157.) 
13. Dorsal valve of a defective specimen, much enlarged, showing the numerous divaricated rays. 
13 a, portion of surface, showing the transverse beading, x 20. 
DisciIna PELTASTES, n. sp. (Page 159.) 
14. Ventral valve, enlarged, seen from within, slightly dislocated by crushing, showing a minute 
tube which is accidentally fractured above, and whose foramen below is concealed by pressure ; 
showing also an anterior callosity and the surface-ornament. 
